Note 2 - Summary of Significant Accounting Policies - Leases (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2019
Operating Lease, Liability	$ 110	$ 200
Operating Lease, Right-of-Use Asset	$ 100	$ 200
Accounting Standards Update 2016-02
Operating Lease, Liability			$ 300
Operating Lease, Right-of-Use Asset			$ 300